Blackjack players who “count cards” keep track of cards that have already been played and use this knowledge to turn the probability of winning in their favor. Though casinos try to eject card counters or otherwise make their task more difficult, card counting is perfectly legal. So long as card counters rely on their own memory and computational skills, they have violated no laws and can make sizable profits. By contrast, if players use a “device” to help them count cards, like a calculator or smartphone, they have committed a serious crime.I consider two potential justifications for anti-device legislation and find both lacking. The first is that, unlike natural card counting, device-assisted card counting requires cognitive enhancement. It makes card counting less natural and is unfair to casinos and should therefore be prohibited. The second potential justification relies on the privacy of our thoughts. On this view, natural card counting is a kind of cheating that warrants punishment. We do not criminalize natural card counting, however, because such laws would interfere with our thought privacy. Since concerns about thought privacy are less applicable to device-assisted counting, we can prohibit device-assisted counting without violating our rights to freedom of mind. While I do not purport to show that these justifications are hopeless, I present reasons to doubt that they will ultimately prove successful.